1. Field of the Invention
The present invention relates to a digital magnetic recording/reproducing apparatus such as a digital video tape recorder (DVTR).
2. Description of the Prior Art
As higher definition is demanded for video signals, the data rate of recording and reproducing signals tends to be higher in the digital signal magnetic recording and reproducing apparatus. For raising the data rate of recording and reproducing signals, together with the increase of data rate per channel, it is being studied to lower the data rate per channel by increasing the number of channels and dividing the input signals, which is known as multi-channel design.
In the conventional digital signal magnetic recording/reproducing apparatus, when recording multi-channel signals by using a plurality of magnetic heads mounted on a rotary cylinder, signals of individual channels are transmitted into the rotary cylinder through a rotary transformer independently. Further, the recording current is adjusted by once adjusting the signal level in the circuit outside the rotary cylinder, and transmitting into the rotary cylinder (for instance, M. Umemoto, Y. Eto, H. Sawamura and H. Katayama, "High data rate recording for HDTV digital VTR," IEEE, Transactions on Magnetics, Vol. 24, No. 6, p. 2407, 1988).
However, in the constitution for transmitting the signals of individual channels into the rotary cylinder through a rotary transformer independently, as many channels of the rotary transformer are required as the number of channels of recording signals. As the number of the channels of rotary transformer increases, the size of the rotary transformer becomes larger, and the loads on the motor and its control circuit for driving the rotary cylinder increase. If attempted, to the contrary, to reduce the size of the rotary transformer, the crosstalk between channels increases, and the signal deteriorates.